Endoscopy is a technology that allows minimally-invasive viewing of internal features of the body of a patient. In medicine, endoscopy allows acquisition of high-quality images of internal features of a human body without the need for invasive surgery. The basic tool of endoscopy is the endoscope, which is inserted into the patient's body to be viewed. Some endoscopic procedures involve the use of a flexible scope, as in the medical field of gastroenterology, for example. Other medical procedures, such as arthroscopy or laproscopy, use a rigid scope. The scope is normally coupled to a high-intensity light source that transmits light into the body through the scope. Reflected light representing images of the body interior then enters the scope and is directed to a camera head that includes electronics for acquiring video image data. The camera head is typically coupled directly to a video monitor or other display device, or alternatively to an intermediate video processing system, for displaying and/or recording the video images acquired by the camera.
In traditional endoscopes, a wired connection (i.e., cable) is used to physically connect the camera head to a video monitor or processing system. Images viewed by the endoscope are converted to video image data by the camera head and then transmitted over the wired connection to the video monitor for display.
Unfortunately, the presence of the wired connection between the camera head and monitor lead to various complications. First, the presence of a wired connection on the camera head makes it difficult for the surgeon to operate since the wired connection often interferes with free movement of the endoscope. In addition, a camera head utilizing a wired connection poses a greater risk of contamination during surgery. The endoscope and associated camera head are surgical tools, and as such, are utilized within the “sterile field”, a defined area around the patient where only sterilized objects are allowed. However, the devices that connect to the camera head, i.e., video monitor, video recorder, etc., cannot be sterilized, and thus must be maintained outside the sterile field. The wired connection subsequently complicates the maintaining of a sterile field since a physical link exists between the sterile camera head and the non-sterile monitor.
To address the above problems, manufacturers have begun producing endoscopic camera heads that incorporate a transmitter for wirelessly conveying the video image data to the devices outside the sterile field. This, however, leads to various new problems. Wireless communications are frequently subject to various types of electromagnetic interference, resulting in the camera heads being unreliable. Disruption of the wireless signal due to obstruction can also be a problem. During a procedure, a surgeon may frequently change their hold on the camera head or endoscope, resulting in the antenna of the camera head to be covered over or blocked. Surgeons can also be quite mobile during a procedure, changing their position relative to the patient's body in order to improve their view or obtain better access. Consequently, the position of the camera head can change frequently, thereby increasing the chance that the wireless signal path may become obstructed by an object in the room or even by the surgeon's body. Additionally, the wireless connection between the camera head and monitor can be limited to a relatively low rate of data transfer, thereby restricting the transfer of the more bandwidth intensive high-fidelity digital video signal. Limitations in the image compression schemes typically utilized by existing endoscopic cameras also tend to decrease the reliability of the wireless connection as well as impose limitations on the quality of the video.